In the mobile communication system, a holder (user) of a terminal device (also called a “mobile terminal” or a “radio terminal”, hereinafter referred to as a “terminal”) pays a communication operator who provides communication service a fee (usage charge) to receive communication service including voice communication and data communication using the terminal. For example, a method of determining a fee based on an amount of information related to a communication service (communication traffic) is referred to a usage based fee.
Usage fee payment methods include a prepaid method that allows a user to use communication service within a fee range of a prepaid fee, a method of a bank account payment that allows a user to pay a usage fee through a bank account, and a card settlement method that allows a user to pay a usage fee through a credit card issued by a credit card company.
When the bank account transfer or the credit card payment is used, the user in advance applies to the operator for a bank account number and a credit card number of a credit card. The bank account number and the card number are registered as information according to which a usage fee is billed. The registration of a plurality of bank accounts or a plurality of card numbers is not ordinarily performed. More specifically, each terminal is associated with a particular bank account number or a particular card number.
It is now contemplated in the mobile communication system that a person other than the right user may use the terminal of the right user. For example, there are times when a person holds no terminal or when a person holds a terminal but currently does not carry it.
In such a case, a public telephone may be used. However, as the mobile communication system is in widespread use, the number of available public telephones decreases. This presents a difficulty in the use of public telephones. A person may temporarily borrow a terminal of another person and use it. In such a case, a fee (including one for a telephone communication and a data communication) is billed to the holder of the terminal. The user pays the holder of the terminal the fee in any way.
Techniques related to terminal borrowing are described below. For example, a person having a personal telephone number may communicate using a borrowed mobile telephone terminal. A number reading circuit reads a credit card number and sends the credit card number to a line controller. The line controller sends a personal telephone number corresponding to the credit card number to the borrowed mobile telephone terminal. The terminal writes the received personal telephone number on a personal telephone number memory therewithin, thereby changing the personal telephone number (as described in Japanese Laid-open Patent Publication No. 4-342324).
It is difficult and complex to calculate a fee incurred in the borrowing and pay the terminal holder the fee. In the related art described in Japanese Laid-open Patent Publication No. 4-342324, the telephone number of the borrowed mobile terminal is changed to the personal telephone number of the borrower so that the borrowed telephone terminal is set to be identical in state to a terminal held by the user of the borrowed mobile telephone terminal. In this way, the problem related to the billing is solved.
However, the related art suffers from the following problem. Firstly, the related art assumes that the borrower has a personal telephone number. A person having no personal telephone number has difficulty in using the borrowed mobile telephone terminal.
Secondly, in accordance with the related art, the personal telephone number is sent to the borrowed mobile telephone terminal, and the borrowed mobile telephone terminal is changed to have the personal telephone number. The borrowed mobile telephone terminal is thus usable. In current standard specifications of terminals, the terminal includes a subscriber identity module (SIM) card storing a telephone number and a unique identification (ID) identifying the telephone number, and the unique ID is solidly associated with the telephone number. A physical structure (a terminal structure, for example) of an IC card used as a SIM card is not formed on the assumption that the stored telephone number is changed. For this reason, the change of the telephone number is difficult to contemplate.